Texas Instruments TI InterActive! Getting Started Manual page 55

Math updates
The TI InterActive! math system is dynamic
and performs updates of all variables whenever
a new object is defined, modified, or moved.
This feature enables new ways in which to
illustrate ideas and concepts. It may also
require some experience in order to know what
to expect.
Each object has an evaluation point that determines when its
information is available for evaluation by the math system.
Evaluations occur in a specific order.
Objects whose evaluation point appears above or to the left
of other objects' evaluation points are evaluated first.
Subsequent objects are evaluated in this spatial order until all
objects in the document are evaluated.
This evaluation occurs many times during the course of creating
or editing a document. The example below illustrates the
importance of the math evaluation order.
Document 1
In , is defined as
Document 1 a
Boxes on the same line. In
reversed, and is defined as
a
Boxes on the same line. The position of the second Math Box is
significant to the evaluation of the third Math Box, which
contains the expression
to when the third Math Box is evaluated. In the second
30
document, is equal to
a
and in consecutive Math
20 30
, the definition order is
Document 2
and again in consecutive Math
30 20,
. In the first document,
factor(a)
when the third Math Box is evaluated.
20
Getting Started with TI InterActive!
Document 2
is equal
a
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